1. Field of the Invention
The present invention relates to the field of automated sorting and inspection apparatus.
2. Prior Art
Various types of automated or semiautomated sorting and inspection apparatus and methods are well known in the prior art. The assignee of the present invention, for example, has manufactured and sold equipment for automatically sorting containers, such as by way of example, returnable soft drink bottles. That apparatus includes a transport system for receiving bottles from an inlet conveyor and for releasing the bottles, based upon a determination of their character, onto any of multiple output conveyors. Identification of the bottles is done by using various sensors to sense readily identifiable characteristics of each bottle in the system as it passes the sensors. For instance, feelers may sense the bottle height or bottle diameter, color sensitive photo optical sensors may sense glass color, etc. Typically the sensors are disposed along or around the transport system so that the sensing of a final characteristic identifying a particular bottle will immediately result in the discharge of that bottle onto the adjacent output conveyor. Such systems operate well under certain conditions, though have various limitations in terms of setup and adjustment time, and of course cannot be effectively used to separate bottles which cannot be characterized by relatively gross, easily sensed parameters. In addition, such devices lack certain flexibility, even when all bottles to be separated have detectable differences, as those detectable differences sometimes pedetermine the order in which the bottles can be identified and thus the order in which they will pass to the respective output conveyors, contrary to an otherwise desired order of output.
Devices of the foregoing type and/or related devices are disclosed in U.S. Pat. Nos. 2,800,226, 2,821,302, 3,358,552, 3,411,625, 3,430,766, and 3,589,513.
U.S. Pat. Nos. 3,997,780, 3,997,781, 4,051,366, and 4,074,130, all filed on the same data, relate to a system for orienting labeled containers so that the labeled containers in a six pack will all be oriented with the labels facing outward. The general system operates on 24 bottles simultaneously, using 24 lenses feeding optical fiber bundles direction to a vidicon camera. The bottles are rotated, and for each of the spinning bottles, the vidicon camera output is quantized, stored and compared repetively over successful cycles, with an eight-bit pattern of four digital "dark" bits followed by four digital "white" bits, a match indicating that a label edge has passed the sensing station several cycles previously so that the bottle may be stopped in a desired position following a settable delay. In essence, the vidicon camera is merely providing a device for multiplexing the 24 sensor signals so that the overall system can sense the edge of a predetermined label on 24 rotating bottles, all of the same bottle and label design. In a second embodiment, photo detectors replace the light pipes and vidicon camera, a serial memory replaces the random access memory used in the data reduction system of the first embodiment, and the label patterns are sensed with optional "Don't care" bits to allow for a fixed predetermined maximum inaccuracy in the sensing.
In U.S. Pat. No. 3,955,179, a system is disclosed using multiple light sensors, fixed at predetermined locations to sense certain overall bottle characteristics as bottles pass thereby. Sensor signals are provided to a computer circuit which is programmed to provide an output corresponding to the value of a given bottle passing through the sensing stage. The system is operable on the shadow of the bottle, with a computer programming unit comprising a programming panel which is programmed by selectively providing interconnections by way of switches or connecting plugs between selected row and column lines. The sensors themselves are also adjustable in position so that the system must be manually programmed and adjusted for the various size and shape bottle to be detected.
Finally, U.S. Pat. No. 4,002,823 discloses a method and apparatus for video inspection of articles of manufacture which utilizes a semi-diffused light source positioned adjacent one side of and optically spaced from the article being inspected for and illuminating the article. A video camera is positioned on the opposite side of the article from the diffused light source and scans the illuminated article in order to produce a video signal indicative of the difference in the refraction characteristics of the article to thereby indicate the presence or absence of defects in the glass where sampled. The video signal is appropriately filtered and then coupled to a peak detector for detecting flaws of unacceptable magnitudes.